Optical proximity sensors, such as the AVAGO TECHLOGIES™ HSDL-9100 surface-mount proximity sensor and the AVAGO TECHLOGIES™ APDS-9101 integrated reflective sensor, are known in the art. Such sensors typically comprise an integrated high efficiency infrared emitter or light source and a corresponding photodiode or light detector. Referring to FIG. 1, there is shown a prior art optical proximity sensor 10 comprising infrared light emitter 20, light emitter driving circuit 21, light detector or photodiode 30, light detector sensing circuit 31, metal housing or shield 40 with apertures 41 and 42, and object, to be sensed 50. Light rays 22 emitted by emitter 20 and reflected from object 50 (which is in relatively close proximity to optical proximity sensor 10) are detected by photodiode 31 and thereby provide an indication that object 60 is close or near to sensor 10.
As further shown in FIG. 1, optical proximity sensor 10 further comprises metal housing or shield 40 formed of metal and comprising apertures 42 and 43 located over light emitter 20 and light detector 30, respectively, such that at least a first portion of light 22 emitted by light detector 20 passes through aperture 43, and at least a second portion of the first portion 22 of light reflected from object 50 in proximity to sensor 10 passes through aperture 42 for detection by light detector 20. As shown, metal housing or shield 40 further comprises first and second modules 41 and 44 within which light emitter 20 and light detector 30 are disposed, respectively. The first and second modules 41 and 44 comprise adjoining optically opaque metal inner sidewalls 45 to provide optical isolation between first and second modules 41 and 44.
Sensors such as the HSDL-9100 generally include a metal shield, such as shield or housing 40 shown in FIG. 1, to provide optical isolation between light emitter 20 and photodiode 30 so that undesired optical cross-talk between emitter 20 and detector 30 is minimized. See, for example, the Data Sheets corresponding to the AVAGO TECHLOGIES™ HSDL-9100 Surface-Mount Proximity Sensor and the AVAGO TECHLOGIES™ APDS-9101 integrated Reflective Sensor, each of which is hereby incorporated by reference herein, each in its respective entirety.
FIG. 2 shows a prior art optical proximity sensor 10 with metal shield or housing 40 that, has been damaged during the process of preparing sensor 10 for mounting on a printed circuit board. (Sensor 10 shown in FIG. 2 is a surface mount device or SMD, and comprises printed circuit board or PCB substrate 61, which is configured to permit sensor 10 to be attached to an underlying PCB, not shown in FIG. 2.) As shown in FIG. 2, top covers 43 and 44 of housing 40 have been bent upwardly during handling of sensor 10 by automated assembly machinery, resulting in optical proximity sensor 10 becoming unusable for its intended function or purpose as an SMD optical proximity sensor mounted on a printed circuit board. It is believed that sponge-like material on the assembly machinery engages and protrudes through one or both of apertures 41 and 42 but does not subsequently release adequately therefrom, resulting in the damage to top covers 43 and 44 shown in FIG. 1
What is needed is a metal housing or shield for an optical proximity sensor that is easily manufacturable at low cost but that is also sufficiently structurally robust to resist undesired mechanical deformation during the manufacturing and assembly process.